A late Gary Kenneth equaliser denied on-loan Dundee striker Mickael Antoine-Curier from marking a memorable return to the City of Discovery with Hamilton Accies.
Curier's 65th minute strike was tinged with controversy, with the Guadeloupe internationalist appearing to be offside.
United were missing a host of attacking players, including top scorer Danny Cadamarteri, and looked on course to suffer back-to-back home defeats.
Kenneth though darted onto a Damian Casalinuovo cross to head home a 93rd minute equaliser past a helpless Tomas Cerny.
Chances were few and far between in a dismal first 45 minutes, with the visitors Hamilton having the two best opportunities of the half. Curier saw a goalbound header blocked, before Marco Paixao blazed a glorious chance over from 10 yards.
The visitors though made the breakthrough midway through the second half when Curier incensed the Tannadice crowd with a controversial goal.
The United players had stopped playing as James McArthur chipped the ball through to Curier, who paused for a moment expecting the referee's whistle to come.
It didn't however and he slotted the ball past a bewildered looking Nicky Weaver in the United goal.
Arabs boss Craig Levein threw on Dale Hilson for his debut in place of recent Scotland cap Craig Conway in search of an equaliser but struggled to seriously threaten until the dying minutes.
Casalinuovo headed against the post with two minutes remaining and Darren Dods then smashed the rebound against the crossbar as the Accies clung on.
But their resolve was to be broken with seconds remaining when Kenneth sprinted onto Casalinuovo's cross to bring the home crowd to its feet.
